Accept all 3.3.x and 3.4.x Ruby versions for Prism.parse

ext/prism/extension.c

@@ -770,8 +770,10 @@ parse_input(pm_string_t *input, const pm_options_t *options) {
  * * `version` - the version of Ruby syntax that prism should used to parse Ruby
  *       code. By default prism assumes you want to parse with the latest version
  *       of Ruby syntax (which you can trigger with `nil` or `"latest"`). You
- *       may also restrict the syntax to a specific version of Ruby. The
- *       supported values are `"3.3.0"` and `"3.4.0"`.
+ *       may also restrict the syntax to a specific version of Ruby, e.g., with `"3.3.0"`.
+ *       To parse with the same syntax version that the current Ruby is running
+ *       use `version: RUBY_VERSION`. Raises ArgumentError if the version is not
+ *       currently supported by Prism.
  */
 static VALUE
 parse(int argc, VALUE *argv, VALUE self) {

lib/prism/ffi.rb

@@ -411,6 +411,20 @@ def dump_options_command_line(options)
       end
     end
 
+    # Return the value that should be dumped for the version option.
+    def dump_options_version(version)
+      case version
+      when nil, "latest"
+        0
+      when /\A3\.3\.\d+\z/
+        1
+      when /\A3\.4\.\d+\z/
+        0
+      else
+        raise ArgumentError, "invalid version: #{version}"
+      end
+    end
+
     # Convert the given options into a serialized options string.
     def dump_options(options)
       template = +""
@@ -443,7 +457,7 @@ def dump_options(options)
       values << dump_options_command_line(options)
 
       template << "C"
-      values << { nil => 0, "3.3.0" => 1, "3.3.1" => 1, "3.4.0" => 0, "latest" => 0 }.fetch(options[:version])
+      values << dump_options_version(options[:version])
 
       template << "C"
       values << (options[:encoding] == false ? 1 : 0)

src/options.c

@@ -1,4 +1,5 @@
 #include "prism/options.h"
+#include "prism/util/pm_char.h"
 
 /**
  * Set the shebang callback option on the given options struct.
@@ -57,47 +58,42 @@ pm_options_command_line_set(pm_options_t *options, uint8_t command_line) {
     options->command_line = command_line;
 }
 
+static bool is_number(const char *string, size_t length) {
+    return pm_strspn_decimal_digit((const uint8_t *) string, (ptrdiff_t) length) == length;
+}
+
 /**
  * Set the version option on the given options struct by parsing the given
  * string. If the string contains an invalid option, this returns false.
  * Otherwise, it returns true.
  */
 PRISM_EXPORTED_FUNCTION bool
 pm_options_version_set(pm_options_t *options, const char *version, size_t length) {
-    switch (length) {
-        case 0:
-            if (version == NULL) {
-                options->version = PM_OPTIONS_VERSION_LATEST;
-                return true;
-            }
-
-            return false;
-        case 5:
-            assert(version != NULL);
-
-            if ((strncmp(version, "3.3.0", length) == 0) || (strncmp(version, "3.3.1", length) == 0)) {
-                options->version = PM_OPTIONS_VERSION_CRUBY_3_3;
-                return true;
-            }
-
-            if (strncmp(version, "3.4.0", length) == 0) {
-                options->version = PM_OPTIONS_VERSION_LATEST;
-                return true;
-            }
+    if (version == NULL) {
+        options->version = PM_OPTIONS_VERSION_LATEST;
+        return true;
+    }
 
-            return false;
-        case 6:
-            assert(version != NULL);
+    if (length >= 4) {
+        if (strncmp(version, "3.3.", 4) == 0 && is_number(version + 4, length - 4)) {
+            options->version = PM_OPTIONS_VERSION_CRUBY_3_3;
+            return true;
+        }
 
-            if (strncmp(version, "latest", length) == 0) {
-                options->version = PM_OPTIONS_VERSION_LATEST;
-                return true;
-            }
+        if (strncmp(version, "3.4.", 4) == 0 && is_number(version + 4, length - 4)) {
+            options->version = PM_OPTIONS_VERSION_LATEST;
+            return true;
+        }
+    }
 
-            return false;
-        default:
-            return false;
+    if (length >= 6) {
+        if (strncmp(version, "latest", 7) == 0) { // 7 to compare the \0 as well
+            options->version = PM_OPTIONS_VERSION_LATEST;
+            return true;
+        }
     }
+
+    return false;
 }
 
 /**

test/prism/version_test.rb

@@ -4,8 +4,46 @@
 
 module Prism
   class VersionTest < TestCase
-    def test_version_is_set
+    def test_prism_version_is_set
       refute_nil VERSION
     end
+
+    def test_syntax_versions
+      assert Prism.parse("1 + 1", version: "3.3.0").success?
+      assert Prism.parse("1 + 1", version: "3.3.1").success?
+      assert Prism.parse("1 + 1", version: "3.3.9").success?
+      assert Prism.parse("1 + 1", version: "3.3.10").success?
+
+      assert Prism.parse("1 + 1", version: "3.4.0").success?
+      assert Prism.parse("1 + 1", version: "3.4.9").success?
+      assert Prism.parse("1 + 1", version: "3.4.10").success?
+
+      assert Prism.parse("1 + 1", version: "latest").success?
+
+      # Test edge case
+      error = assert_raise ArgumentError do
+        Prism.parse("1 + 1", version: "latest2")
+      end
+      assert_equal "invalid version: latest2", error.message
+
+      assert_raise ArgumentError do
+        Prism.parse("1 + 1", version: "3.3.a")
+      end
+
+      # Not supported version syntax
+      assert_raise ArgumentError do
+        Prism.parse("1 + 1", version: "3.3")
+      end
+
+      # Not supported version (too old)
+      assert_raise ArgumentError do
+        Prism.parse("1 + 1", version: "3.2.0")
+      end
+
+      # Not supported version (too new)
+      assert_raise ArgumentError do
+        Prism.parse("1 + 1", version: "3.5.0")
+      end
+    end
   end
 end